Hantavirus has once again come under the spotlight of public health authorities following several recent outbreaks and an increase in cases in endemic regions. Although the overall risk remains low, the current situation highlights a key aspect for healthcare professionals: the importance of early differential diagnosis.
Current hantavirus situation
During the 2025–2026 epidemiological season, Argentina has reported a significant increase in hantavirus cases, exceeding 100 confirmed infections and showing a high mortality rate (1). This sustained rise has placed the number of infections above the outbreak threshold in several regions of the country (1).
In addition, in May 2026, an international outbreak linked to a cruise ship was reported, involving several severe cases and confirmed deaths associated with the Andes virus variant (2). This variant is particularly relevant because, unlike other hantaviruses, it can demonstrate limited person-to-person transmission in situations of close contact (2).
Despite these events, organisations such as the ECDC and the Spanish Ministry of Health consider the risk to the general population to be low, provided that epidemiological surveillance is maintained (3).
Hantavirus symptoms: why it is difficult to diagnose
One of the main challenges with hantavirus is that its early symptoms are non-specific and common to many infections. In the initial stages, patients may present with:
- Fever
- Muscle pain
- Headache
- Gastrointestinal symptoms
In some cases, the disease may rapidly progress to severe conditions such as pneumonia, acute respiratory distress syndrome, or shock (2).
This variable clinical course, together with an incubation period of up to several weeks, makes early diagnosis difficult and increases the risk of confusion with other diseases (1).
Differential diagnosis of hantavirus: diseases to rule out
Differential diagnosis of hantavirus is essential, as its symptoms can easily be mistaken for other respiratory and systemic infections. The main conditions to consider include:
- Influenza and other respiratory viruses
- COVID-19
- Viral or bacterial pneumonia
- Dengue
- Leptospirosis
- Sepsis (1)
This clinical overlap makes it essential to combine symptom assessment with epidemiological context (travel history, exposure to rodents) and specific laboratory techniques such as PCR or serology (4).
Importance of syndromic testing
In scenarios where multiple pathogens share similar symptoms, the traditional approach based on individual tests may prove insufficient. For this reason, syndromic testing has become a key diagnostic strategy.
This approach enables the simultaneous detection or exclusion of multiple infectious agents in patients with similar clinical presentations, making it particularly useful in:
- Acute respiratory infections
- Fever of unknown origin
- Emerging or imported diseases
In the case of hantavirus, the ability to rapidly rule out more common infections is essential to guide diagnosis and clinical management.
Vitassay solutions for differential diagnosis
At Vitassay, we develop molecular diagnostic solutions designed to address these clinical challenges. Yes, we are on it!
Our range of kits supports the differential diagnosis of infections with overlapping symptoms, including:
- Kits for respiratory viruses, such as influenza or SARS-CoV-2
- Assays for bacterial pathogens associated with pneumonia
- Solutions for tropical diseases, such as dengue
Thanks to these tools, laboratories can identify or rule out multiple pathogens quickly and accurately, optimising turnaround times.
Although hantavirus requires specific confirmation, having solutions that facilitate early differential diagnosis is key to improving clinical decision-making and public health response.
Sources
(1) OPS – Hantavirus, síntomas y diagnóstico diferencial: https://www.paho.org/es/temas/hantavirus
(2) ECDC – Andes Hantavirus outbreak in cruise ship: https://www.ecdc.europa.eu/en/infectious-disease-topics/hantavirus-infection/surveillance-and-updates/andes-hantavirus-outbreak
(3) Ministerio de Sanidad – Evaluación del riesgo en España: https://www.sanidad.gob.es/en/gabinete/notasPrensa.do?id=6897
(4) SEIMC – Diagnóstico microbiológico y recomendaciones clínicas: https://seimc.org/wp-content/uploads/2026/05/seimc-rc-2026-decalogo-hantavirus.pdf7